A device under test such as a semiconductor device is subjected to an electrical test (inspection) as to whether or not it works as shown in a specification. In the device under test, an electrode such as, for example, a bump electrode is formed, and for its electrical test, the device under test is connected to a tester through an electrical connecting apparatus such as a probe card provided with probes (contacts) whose tips are pressed against the electrode.
There is such an electrical connecting apparatus comprising a probe board, a base portion combined with the probe board, an elastically deformable arm portion extending above the electrode of the device under test from the base portion along the probe board at a distance therefrom, and a tip portion projecting from the arm portion in a direction to be away from the probe board (see, e.g., Patent Documents 1 to 4).
[Patent Document 1] Japanese Patent Appln. Public Disclosure No. 2002-340932.
[Patent Document 2] Japanese Patent Appln. Public Disclosure No. 2003-43064.
[Patent Document 3] Japanese Patent Appln. Public Disclosure No. 2003-227849.
[Patent Document 4] National Patent Public Disclosure No. 2002-509604.
As an electrode to receive such a probe tip, there is a bump electrode 2 formed on a semiconductor wafer 1 as shown in FIG. 6(a). The upside 3 of the bump electrode 2 is flat except a recess 4 formed in the center. The peripheral wall 4a of the recess 4 is an inclined surface, and a frame-like flat surface area 3a surrounding the recess 4 is formed continuously on the inclined surface 4a. 
Such a bump electrode 2 is formed by forming in general a mask for selectively exposing the area for the bump electrode 2 on the semiconductor wafer 1 with a photo resist and depositing a bump electrode material in the exposed area. At the time of depositing the bump electrode material, the recess 4 is undesirably formed.
Since the inclined surface 4a of the recess 4 as mentioned above hinders a stable electrical contact between the tip 5a of a probe 5 and the bump electrode 2, the probe 5 used to be disposed, as shown in FIG. 6(a), with its tip in correspondence to one half area on the side proximal to the probe 5 in the flat surface area 3a so as to make the tip 5a contact the flat surface area 3a of the bump electrode 2.
By this probe arrangement, as shown in FIG. 6(b), when the probe 5 is approached relatively to the bump electrode 2, the tip 5a contacts the flat surface area 3a. Thereafter, by further bringing the probe 5 relatively close to the bump electrode 2, as shown in FIG. 6(c), an overdrive force which may cause deflection to the arm portion 5b of the probe 5 acts on the probe 5, and therefore, with an elastic deformation of the arm portion 5b, the tip 5a of the probe 5 is caused displacement in an extending direction of the arm portion 5b, thereby sliding on the upside 3 of the bump electrode 2 to chip off. By the sliding of the tip 5a, a surface oxide film of the bump electrode 3 is partially removed, thereby ensuring a sure electrical contact between the bump electrode 3 and the tip 5a. 